Heptrix is a traditional Tetriminos and line-clearing game developed by Jose Varela. It is a real 3D game that can be played offline without the need for wifi. The game is completely free and does not include any in-app purchases.

The gameplay of Heptrix is similar to Tetris, where the player needs to clear lines by fitting falling Tetriminos into a well. The game can be controlled using buttons to move left, right, rotate, and drop, or by swiping left, right, up, and down. To complete a level, the player needs to clear seven lines. Each piece landed gives seven points, and each line cleared gives 70 points, which increases exponentially by the number of simultaneous lines.

Overall, Heptrix is a fun and challenging game for puzzle lovers. It is compatible with Android 9.0 and can be played offline without any interruptions. The game's real 3D experience adds to the excitement, and the absence of in-app purchases makes it a great choice for those who want to play without any monetary commitments.